Aconcrete pump of 120-cy/hr max. output is used to place 250 cy of concrete. it is supplied by 8 cy transit-mix trucks arriving to the site every 15 mins. barring interruptions how many hours will the operation require, considering 80% efficiency factor?

An ideal otto cycle has a compression ratio of 10.5, takes in air at 90 kpa and 40°c, and is repeated 2500 times per minute. using constant specific heats at room temperature, determine the thermal efficiency of this cycle and the rate of heat input if the cycle is to produce 90 kw of power.